Residential customers will see an average rise of 18 per cent under AGL, 19.9 per cent from EnergyAustralia, 16.1 per cent with Origin Energy.

Bruce Mountain, the head of a private energy consultancy firm, said the increases would see South Australia take the lead on world power prices — but for all the wrong reasons.

"After taxes, the [typical] household in South Australia will be paying slightly more than the [typical] household in Denmark, which currently has the highest prices in the world," Mr Mountain said.

"These things are complex — just because the statement might be true for the representative customer might not mean it's true for you.

"But the broad picture is that these prices can be thought of as the highest in the world."

Mr Mountain made the prediction based on national and international energy market data, and papers published by the Council of European Energy Regulators and OECD.

Power prices exceed value

He said the price Australian customers, particularly South Australian customers, were currently paying for power exceeded the actual value of electricity as a resource.

"I think it is surprising that [power prices] have continued to rise as they have and the latest increases are remarkable — the household price going up by around a fifth on top of the existing prices is extraordinary," he said.

"This is a very well established service, it's been around for many years [and] it's very rare to see such large increases in retail electricity from one year to the next.

"I don't believe it's matched by the aggregate cost in the supply chain.

"Our markets are not working well, and it goes from the operation of the retail market, to the wholesale market, to the regulatory oversight of networks."

Yesterday, an Adelaide plastic recycling business announced it was forced into liquidation partly due to exorbitant power prices.